<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="./js/vue.js"></script>
</head>
<body>
    <div id="app">
        <div ref="damu">
            xxxx
        </div>
        <button @click="handleC">click</button>
        <list ref="list"></list>
    </div>
</body>
<script>
    Vue.component("list",{
        data(){
            return  {
                msg:"1234"
            }
        },
        template:`<p>{{msg}}</p>`
    })

    var vm = new Vue({
        el:"#app",
        methods:{
            handleC(){
                console.log(this.$refs.list.msg)
            }
        }
    })
</script>
</html>